Conveniently arrange all the ingredients. Wash the vegetables and peel them.
Boil the beef tongue. Place the tongue in a pan of water. Squeeze the juice from half a lemon and add to the pan, add the onion, parsley root and whole carrot to the broth, salt and all the spices on the list. Leave for two hours. Then wash and clean your tongue well and rub it with the remaining lemon to remove the smell. Cool on a plate.
Make the broth. Take out the vegetables. Lighten the broth with egg white. Whisk the whites and place in a saucepan with broth, boil for 5 minutes. Strain the broth using cheesecloth.
Prepare gelatin. Take 500 ml of hot broth and pour gelatin into it, stir until completely dissolved.
Fill your tongue with broth. Take a large dish and pour the broth with gelatin in a 0.3 cm layer. Place in the refrigerator until the gelatin hardens. It will take about 20 minutes. Cut the cooked tongue into slices 5 mm wide. Place the pieces of meat on the frozen broth on a platter. Scatter the peas nicely. Cut the cooked carrots into circles or stars, place on a dish, add small sprigs of parsley. Pour in the rest of the broth with gelatin. Place in the refrigerator to harden.
Decorate the finished tongue in jelly with a pattern of mayonnaise and parsley leaves.